Lighting, Light Fixtures, Ceiling and Exhaust Fans - Old Wiring for Light Switch - 5 wires?
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Vorpal
08-20-04, 09:35 PM
I am trying to replace a switch/socket device with a double switch device in the bathroom. I would like one switch to control the light and one switch to control the bathroon fan.
The wiring is very old - late 1940's. It has romex shielding. There are two romex coils behind the wall where the switch is located. One romex has two wires, the other romex has three wires. There is also a new wire pair that leads to the bathroom fan.
The existing wall switch is a combo unit obviously not the original equipment. There is a switch on top that activates both the light and the fan. There is a three prong socket on the bottom that only works when the light is turned on.
I tried to install a double switch wall device. I hooked the old wires up to the same posts and added the new wires for the fan to the bottom posts. But, when I flip the breaker, it trips immediately.
The really wierd thing is the five existing wires in the two romex coils. Out of the five, only one is hot. Using a light meter (110V light comes on). Why are there five wires? Shouldn't there only be four?
The wiring is very old - late 1940's. It has romex shielding. There are two romex coils behind the wall where the switch is located. One romex has two wires, the other romex has three wires. There is also a new wire pair that leads to the bathroom fan.
The existing wall switch is a combo unit obviously not the original equipment. There is a switch on top that activates both the light and the fan. There is a three prong socket on the bottom that only works when the light is turned on.
I tried to install a double switch wall device. I hooked the old wires up to the same posts and added the new wires for the fan to the bottom posts. But, when I flip the breaker, it trips immediately.
The really wierd thing is the five existing wires in the two romex coils. Out of the five, only one is hot. Using a light meter (110V light comes on). Why are there five wires? Shouldn't there only be four?
John Nelson
08-20-04, 10:32 PM
If one switch controlled both the light and fan, it is extremely unlikely that controlling them separately is as simple as installing a double switch. You almost certainly need to run more cable in the wall. The reason is that it is very unlikely that the power cables for the light and fan come separately to the switch box. Perhaps you have misunderstood where those wires go. Without Superman X-ray vision, you can usually only guess, and guesses are always dangerous.
The device you installed is a completely different device than the one you removed. Connecting the "old wires up to the same posts" is unlikely to be the correct algorithm.
There are many ways this might be wired, so we need to figure out which one you have. To start this process, I suggest you start by putting everything back exactly as it was before, with the old device, and get it working as it did before. Then tell us all the cables, all the wires, and all the connections in the switch box, in the fan box, and in the light box. Don't tell us where a wire is going to or coming from unless you are 100% sure, and then tell us how you know that for sure.
You also say that there is "a new wire pair that leads to the bathroom fan". Be sure you tell us in excrutiating detail all about that. Did you run them? How many wires? What colors? From where to where? How did you connect it at the fan? How was the fan connected before and what did you do with those wires? Etc, etc, etc. Don't leave anything out.
The device you installed is a completely different device than the one you removed. Connecting the "old wires up to the same posts" is unlikely to be the correct algorithm.
There are many ways this might be wired, so we need to figure out which one you have. To start this process, I suggest you start by putting everything back exactly as it was before, with the old device, and get it working as it did before. Then tell us all the cables, all the wires, and all the connections in the switch box, in the fan box, and in the light box. Don't tell us where a wire is going to or coming from unless you are 100% sure, and then tell us how you know that for sure.
You also say that there is "a new wire pair that leads to the bathroom fan". Be sure you tell us in excrutiating detail all about that. Did you run them? How many wires? What colors? From where to where? How did you connect it at the fan? How was the fan connected before and what did you do with those wires? Etc, etc, etc. Don't leave anything out.